On line model accuracy inspection of model maker rapid prototyping using vision technology

The principle of rapid prototyping (RP, or layer manufacturing) is to fabri cate a 3D object layer by layer. Vision technology has been employed and ha s demonstrated its ability to measure the single-layer profile dimensions o f the Model Maker (MM) RP system model. The on-line profile dimensional ins pection and accuracy analysis;of multiple layers is presented in this paper . The image-processing algorithms, developed to measure the layer profile d imensions, were adapted to process the captured profiled image of multiple layers, layer by layer. Hence, the layer profile dimensions of multiple lay ers were inspected on-line and layer by layer. The problems of vision inspe ction associated with colour mixing of multiple layers are addressed. A col our CCD camera was employed to resolve the colour mixture problem, but it i s too expensive and too much memory is required. A new image difference alg orithm was proposed to solve the problem of colour reflected from adjacent layers. The results demonstrate the promise of online profile dimensions-in spection and accuracy analysis using vision technology.